1. Field of the Invention
The present invention relates to an electrical connector, especially to an electrical connector for connecting a central process unit with a printed circuit board.
2. Description of Related Art
Central Process Unit (CPU) sockets are used to establish electrical connection between a CPU and a printed circuit board. CPU sockets generally include PGA (Pin Grid Array) type and LGA (Land Grid Array) type according to the contact means of between the CPU and the socket.
Conventional PGA socket comprises a base and a cover sliding on the base. The base and cover each have a plurality of passageways for receiving contacts of socket and pins of the CPU, respectively. A plurality of solder balls are attached to the bottom ends of the contacts for soldering to the printed circuit board. The contacts each have a pair of arms whereby define a bigger space and a smaller space therebetween. The pins of CPU firstly pass though the passageways of the cover and located into the bigger space. Then the cover actuates the pins of the CPU to slide in the base and move into the smaller space. In the bigger space, the pins are separated from the contacts and need not to bear insert force from the contacts. After the pins slide into the smaller space, the pair of arms contact with the pins of the CPU so as to establish electrical connection.
LGA socket includes an insulative housing and a plurality of electrical contacts attached to the housing. Each contact has a contact section projecting out of the insulative housing and extending along a predetermined direction thereby increase the density of the electrical contacts.
As discussed above, traditional CPU sockets all need insulative base or housing and metal contacts. However, it is difficult to reduce the height of the traditional socket to the current manufacture level.